1. Field of the Invention
This invention relates generally to aspiration biopsy devices and in particular to such devices which are in the general configuration of a syringe with suitable valves thereon so that a controlled biopsy sample may be taken by one hand operation of the device.
2. Description of the Prior Art
Prior art aspiration biopsy devices include a standard syringe having a needle on the end thereof, wherein the physician operator first depresses the syringe piston completely inwardly, then inserts the needle into the suspect area, probes with the needle into the suspect tissue so that the needle shaves off a sample, and then while holding the barrel of the syringe with one hand, the operator pulls on the piston with the other hand to create a vacuum in the needle and draw some tissue sample into the needle. This is awkward in that two hands are necessary to manipulate the syringe, to draw the tissue sample, particularly when multiple samples are being taken at the same time and the second hand could be more appropriately used for purposes other than holding the syringe.
Another prior art device is like the above device, but includes a holding arrangement between the barrel of the syringe and the piston. In operation, the needle is inserted into the patient, the piston is withdrawn to the location of the holding device, which holds the piston in this location relative to the barrel, at which time the operator can manipulate the device with one hand. Since the needle is in the patient, a vacuum is created in the syringe and the physician can probe to shave off some sample which is drawn in the needle by the vacuum in the syringe. However, upon the syringe being withdrawn from the patient, the locked piston with its created vacuum, quickly draws the sample up the needle and into the barrel of the syringe where the sample is difficult to find and/or manipulate, unless the operator first uses his other hand to unlock the piston and control its movement so that the sample is not drawn into the barrel or ejected from the needle at a non-desired time.
A search of United States patents and foreign patents that was conducted prior to the filing of this disclosure located the following patents of interest in the general field of this invention:
U.S. Pat. Nos. 1,039,591; 2,472,116; 2,863,452 and 3,891,091.
None of the above patents is relevant to the instant invention as claimed. No representation is made or intended that the prior art search was complete or that no better art than that listed is available.